Murray had impressed on his way to the semi-finals for only the second time at Roland Garros only to suffer his worst ever grand slam defeat at the hands of Rafael Nadal.
The Spaniard, who will bid for a ninth title against Novak Djokovic on Sunday, took just an hour and 40 minutes to win 6-3 6-2 6-1, Murray winning only 10 points on Nadal's serve in the match.
Murray will now seek solace in the grass of home, beginning the defence of his Aegon Championships title at Queen's Club on Wednesday before preparing to step out on Centre Court as the reigning Wimbledon champion.
The 27-year-old had certainly expected better of himself, particularly having come close to beating Nadal on clay in Rome three weeks ago.
He hinted it might take him a while to get over the drubbing, but Mouratoglou believes Murray can feel very positive about his form.
The Frenchman, who coaches Serena Williams, told Press Association Sport: "I think everyone was surprised.
"They had this match in Rome that was so good and that Murray played so well. I think that's the match that put him back on track, even though he lost it. We expected at least a battle, and there was no battle at all.
"If you don't put doubts in Rafa's mind, if you don't press on his weaknesses, then of course he's so dangerous. I think Murray let him play, he gave him too much time and he didn't hurt him.
"It was a bad day for him but I think he was too tired. When you're tired against Rafa on clay, you have zero chance, that's it.
"I think it was a very positive Roland Garros for Murray because his game is back to a very good level, and he knows it. This match he forgot already for sure.
"He gained a lot of confidence through this tournament. He knows what he needs to improve because it was obvious in this Roland Garros. Much too many ups and downs, going from offence to defence too many times for no reason."
Attention will now turn back to when Murray will appoint a new head coach, having been without one since splitting from Ivan Lendl in March.
He rated his chances of having someone in place before Wimbledon, the most stressful two weeks of his year, as 50/50.
Mouratoglou said: "We have this saying in France that it's better to be alone than with bad company.
"If he doesn't find the right person yet then he has to wait but for sure it's important to be back with someone with new goals, to have new things to work on in your game, to have a different voice, to have something new to bring excitement back.
"But I think he can do well also without the coach because he has so much experience. He's won two grand slams and he'll have all the crowd behind him at Wimbledon, and he's playing well again.
"He shouldn't panic. If he has someone it's better, but if he doesn't he can still do well."
Murray admitted he would rather have a few days off to lick his wounds and recover from the physical strain of two tough weeks on the clay rather than heading straight onto the grass.
It is at least a much less physical surface while, if Murray needs his spirits lifting, returning to the scene of his greatest triumph should be just the thing.
"I expect to play well there," said the Scot of Wimbledon, which begins on June 23.
"I'm really looking forward to going back. I think it will give me a lot of positive energy.
"I'm glad I'm back playing to a level that was able to get me through to the last stage of slams. I just need that extra few per cent so that I can give myself a chance to try and win them again.
"But the grass will obviously help me. It's a surface I have always enjoyed playing on. I think it's been my most successful surface over my career.
"I'm really looking forward to Wimbledon especially. It's only two and a half weeks away, so I don't have too long to wait."